Combustor for a fuel cell system

Abstract

A combustor generates and supplies hot combustion gases to a fuel reformer. The combustor includes a housing defining a combustion chamber. The combustor also includes a fuel vaporizer having a fuel tube with an electric heating element. The fuel tube is positioned such that a portion thereof extends into the combustion chamber and is exposed to the hot combustion gases exiting the combustion chamber. An electric current is supplied to the electric heating element to vaporize the liquid fuel within the fuel tube when the temperature within the combustion chamber is below is a predetermined temperature. Substantially no electric current is supplied to the electric heating element when the temperature within the combustion chamber is at least the predetermined temperature and the hot combustion gases passing over the portion of the fuel tube extending into the combustion chamber vaporize the liquid fuel within the fuel tube.

1 . A combustor for generating and supplying hot combustion gases to a fuel reformer, said combustor comprising:
 a housing defining a combustion chamber and having an exhaust port for discharging said hot combustion gases therefrom; and   a fuel vaporizer having a fuel tube with an inlet for introducing liquid fuel therewithin, an outlet for dispensing vaporized fuel therefrom to said combustion chamber, and an electric heating element disposed between said inlet and said outlet, wherein a portion of said fuel tube extends into said combustion chamber and is exposed to said hot combustion gases exiting said combustion chamber;   wherein an electric current can be supplied to said electric heating element to vaporize said liquid fuel within said fuel tube when the temperature within said combustion chamber is below a predetermined temperature, and wherein substantially no electric current need be supplied to said electric heating element when the temperature within said combustion chamber is at least said predetermined temperature and said hot combustion gases passing over said portion of said fuel tube are sufficient to supply enough heat to vaporize said liquid fuel within said fuel tube.   
     
     
         2 . A combustor as in  claim 1  wherein said combustion chamber includes a first air inlet for mixing air with said vaporized fuel within said combustion chamber. 
     
     
         3 . A combustor as in  claim 1  wherein said combustion chamber includes a waste gas inlet for mixing waste gas from a fuel cell with said vaporized fuel. 
     
     
         4 . A combustor as in  claim 1  wherein said combustion chamber includes a second air inlet for mixing air with said hot combustion gases within said combustion chamber. 
     
     
         5 . A combustor as in  claim 1  wherein said fuel vaporizer includes a third air inlet for supplying air within said fuel tube. 
     
     
         6 . A combustor as in  claim 1  wherein said portion of said fuel tube is between said outlet of said fuel tube and said exhaust port. 
     
     
         7 . A fuel cell system comprising:
 a fuel reformer for generating reformate from a hydrocarbon fuel;   a fuel cell for generating an electric current, said fuel cell being fluidly coupled to said fuel reformer and receiving said reformate for use in generating said electric current; and   a combustor for generating and supplying hot combustion gases to said fuel reformer, said combustor comprising:   a housing defining a combustion chamber and having an exhaust port for discharging said hot combustion gases therefrom; and   a fuel vaporizer having a fuel tube with an inlet for introducing liquid fuel therewithin, an outlet for dispensing vaporized fuel therefrom to said combustion chamber, and an electric heating element disposed between said inlet and said outlet, wherein a portion of said fuel tube extends into said combustion chamber and is exposed to said hot combustion gases exiting said combustion chamber;   wherein an electric current can be supplied to said electric heating element to vaporize said liquid fuel within said fuel tube when the temperature within said combustion chamber is below a predetermined temperature, and wherein substantially no electric current need be supplied to said electric heating element when the temperature within said combustion chamber is at least said predetermined temperature and said hot combustion gases passing over said portion of said fuel tube are sufficient to supply enough heat to vaporize said liquid fuel within said fuel tube.   
     
     
         8 . A fuel cell system as in  claim 7  wherein said combustion chamber includes a first air inlet for mixing air with said vaporized fuel within said combustion chamber. 
     
     
         9 . A fuel cell system as in  claim 7  wherein said combustion chamber includes a waste gas inlet for mixing waste gas from a fuel cell with said vaporized fuel. 
     
     
         10 . A fuel cell system as in  claim 7  wherein said combustion chamber includes a second air inlet for mixing air with said hot combustion gases within said combustion chamber. 
     
     
         11 . A fuel cell system as in  claim 7  wherein said fuel vaporizer includes a third air inlet for supplying air within said fuel tube. 
     
     
         12 . A fuel cell system as in  claim 7  wherein said portion of said fuel tube is between said outlet of said fuel tube and said exhaust port.